Method of making caterpillar track connectors



p 1-2, 1967 o. KORNER ETAL 3,340,717

METHOD OF MAKING CATERPILLAR TRACK CONNECTORS Filed July 1, 1965 FIG. 1

FIG. 6

FIG. 7

FIG. 8

OTTO KORNER ULRICH WACKER HI!!! qllllll United States Patent 3,340,717 METHOD OF MAKING CATERPILLAR TRACK CONNECTORS Otto Kiirner, Remscheid, and Ulrich Wacker, Wermelskirchen, Germany, assignors to Diehl K.G., Remscheid, Germany Filed July 1, 1965, Ser. No. 468,829 Claims priority, application Germany, July 11, 1964, D 44,919 9 Claims. (Cl. 72-367) The present invention relates to caterpillar track con nectors which are provided with a slot which establishes communication between the two bearing eyes for the track bolts and which pass approximately through the two central axes of said bearing eyes while extending over the entire axial width of the connector. The said slot is adapted to be pressed together against the spring effect of the connector by a clamping screw.

Caterpillar track connectors of the above-mentioned type have heretofore been drop-forged and have then been correspondingly drilled and reamed.

It is an object of the present invention to provide a simplified method of making caterpillar track connectors.

It is also an object of this invention to provide a method of producing caterpillar track connectors of the above mentioned type at considerably reduced costs without impairing the quality thereof.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIGS. 1 to 3 and to 7 respectively illustrate cross sections through two profile strands with different starting and, if desired, also with different end shape in a plurality of successive drawing and rolling stages.

FIGS. 4 and 8 illustrate finished contours made according to the method of the present invention and provided with clamping "screws.

According to the present invention, it is suggested to flat roll a seamlessly drawn steel pipe, especially a steel profile having an inner contour corresponding to the contour to be made, to the outer contour of the connector and to finish draw or finish roll said steel pipe to the rated shape whereupon corresponding sections are cut off or sawed off from the profile strand of the axial width of the connector and are provided with bores and, as the case may be, with a thread for the clamping screw. In order to avoid nonuniform displacements of the material during the finish rolling and finish drawing of the connector-profile strand, a steel profile of different wall thickness may be employed. On the other hand, however, for purposes of compensating for inwardly protruding portions, the broad sides of the connector-profile strand may be provided with depressions or inwardly extending arches. The inner profile may have the shape of two circles, circular segments, polygons, or the like, interconnected by a slot.

Referring now to the drawing in detail, FIG. 1 shows as starting material a seamlessly drawn steel pipe or steel profile 1 the outer contour of which may for instance be cylindrical while the wall thickness, however, is preferably varying so that the said profile or structural steel pipe 1 has two thicker areas 2, 3 and two weaker areas 4, 5 thereby giving the inner surface an elliptic cross sectional shape. However, it should be noted that, if desired, the inner surface may be circular and the outer surface may be elliptical so that the wall thickness will be greater at the upper and at the lower portion. The circumference of such steel profile should be somewhat larger than the circumference of the connector-profile strand to be produced.

For purposes of making the connector profile, first the steel profile 1 is rolled or drawn so that it will have a predetermined wall thickness 2, 3, 4, 5 in conformity with the wall thickness of the finished shape of the connector. Then the steel profile 1 is flat pressed and rolled to a profile 6 (FIG. 2) and finally is finished rolled or drawn so as to assume the shape of the connector profile 7 shown in FIG. 3. The clear inner profile will then have the shape of two circles 9, 10 (FIG. 2) or circular segments 11, 12 (FIG. 3) or polygons interconnected by a slot 8. For purposes of compensating the volume, the broad sides of the profile strand 7 may be provided with inwardly protruding parts 13, 14, depressions 15 or inwardly arched areas 16 in order, when the strand 1 (FIG. 1) or when the profile 6 (FIG. 2) is shaped to the contour profile 7 of FIG. 3, to avoid displacements of material in transverse direction or non-uniform displace-' ments of material in longitudinal direction. A reinforcement of the wall sections 13, 14 may, in order to assure proper strength of these walls, following the drilling of bores 17, 18, 19, 20 (FIG. 4) for a clamping screw 21 on nut 22 therefor, be advantageous when a thread for the clamping screw 21 is cut directly into the walls of connector 7.

When making connectors according to FIG. 4, it is merely necessary to cut off correspondingly long sections from the profile strand 7 (FIG. 3) and to provide the same with the said bores 17, 18, 19, 20 (FIG. 4) for the clamping screw 21 and the clamping screw nut 22.

According to the embodiment shown in FIGS. 5 to 8, a predrawn steel profile 23- (FIG. 5) with circular outer contour has already to a great extent the inner contour 24 of the connector to be made, i.e. the dimensions of the walls of the connector to be made. By broad rolling, this profile 23 is transformed into a strand profile 25 (FIG. 6) the clear inner profile already has the shape of two circular segments 27, 28 interconnected by a slot 26. By a corresponding different shaping of the pre-profile 23 (FIG. 5) it is possible also in this instance to design the bearing eyes 27, 28 (FIG. 6) for the chain bolts as polygons or the like. In conformity with the above mentioned example, sections corresponding to the width of the desired connect-or are cut off from the thus produced finish drawn or rolled profile strand 25, and these sections are then in conformity with FIG. 7 provided with bores 29, 30, 31 or a thread 32 for a clamping screw 33 (FIG. 8). Instead of the bore 31 or thread 32 it is, of course, also possible to provide correspondingly larger bores 19, 20 for a clamping nut 22 similar to the example of FIG. 4.

As will be seen from FIGS. 4 and 8, it is possible by screwing-in clamping members 21, 33 into the clamping nuts 22 or thread 32 to reduce the size of the chain bolt bearing eyes 11, 12; 27, 28 while resiliently decreasing slots 8, 26.

It is, of course, to be understood that the present invention is, by no means, limited to the particular methods shown in the drawing but also comprises any modifications within the scope of the appended claims.

What we claim is:

1. A method of making a caterpillar track connector having two bearing eyes spaced from each other in longitudinal direction of said connector and communicating with each other by a slot extending over the entire width of said connector, the steps of: flat rolling a seamless steel pipe to the approximately outer contour of the connector to be made, finish shaping the thus rolled steel pipe to a rated shape, cutting off from the thus shaped steel pipe a section corresponding in width to the desired Width of the connector to be made, and providing the thus formed work piece with aligned bores respectively arranged in the top and bottom of said work piece with the axes of said bores substantially perpendicular to the plane of said slot for receiving a clamping screw for pulling the central sections of said top and bottom together to reduce the height of said slot to a desired extent.

2. A method according to claim 1, in which said finish shaping of said rolled steel pipe is carried out by a drawing operation.

3. A method according to claim 1, in which said finish shaping of said steel pipe is carried out by a rolling operation.

4. A method of making a caterpillar track connector having two bearing eyes spaced from each other in longitudinal direction of said connector and communicating with each other by a slot extending over the entire width of said connector, the steps of: preparing a seamless steel pipe having two diametrically oppositely located sections of a greater wall thickness than two diametrically oppositely located wall portions of said pipe located in a plane perpendicular to the plane in which said two wall sections of greater wall thickness are located, flat rolling the thus produced seamless steel pipe to the approximate outer contour of the connector to be made, finish shaping the thus rolled steel pipe to a rated shape, cutting otf from the thus shaped steel pipe a section correspond ing in width to the desired width of the connector to be made, and providing the thus formed work piece with aligned bores respectively arranged in the top and bottom of said connector with the axes of said bores substantially perpendicular to the plane of said slot for re ceiving a clamping screw for pulling sections of said top and bottom together to reduce the height of said slot to a desired extent.

5. A method according to claim 4, in which said seamless steel pipe is so shaped as to have an elliptical cross section in which diametrically oppositely located wall portions along the generator axis of said elliptical crosssection have a thinner wall area than diametrically oppositely located wall sections located along the smaller axis of said elliptical cross-section.

6. A method of making a caterpillar track connector having two bearing eyes spaced from each other in longitudinal direction of said connector and communicating with each other by a slot extending over the entire width of said connector, the steps of: preparing a seamless steel pipe having two diametrically oppositely located sections of a greater wall thickness than two diametrically 0ppositely located wall portions of said pipe located in a plane perpendicular to the plane in which said two wall sections of greater wall thickness are located, flat rolling the thus produced pipe so as to move said wall sections of greater wall thickness toward each other to a certain extent while moving the wall sections located in a plane perpendicular to the plane containing said wall sections of greater thickness away from each other thereby producing a relatively flat tubular member with inwardly protruding sections, sharping those outer surface portions of the thus produced tubular member which are located opposite said inwardly protruding sections so as to form inwardly arched surfaces, finish shaping the thus rolled steel pipe to a rated shape, cutting off from the thus shaped steel pipe a section corresponding in width to the desired width of the connector to be made, and providing the thus formed work piece with aligned bores in the area of said arch-shaped surfaces for receiving a clamping screw for pulling said inwardly protruding sections further toward each other.

7. A method according to claim 1, in which the finish shaping of the rolled steel pipe includes the drawing of said steel pipe to a flat tubular member with two cylindrical areas at those portions of said tubular member which have the greatest distance from each other while those portions which are closest to each other confine a slot establishing communication between said cylindrical areas.

8. A method according to claim 1, in which the finish shaping of the rolled steel pipe includes the drawing of said steel pipe to a flat tubular member with two cylindrical segmental areas at those portions of said tubular member which have the greatest distance from each other while those porions which are closest to each other confine a slot establishing communication between said cylindrical segmental areas.

9. A method according to claim 1, in which the finish shaping of the rolled steel pipe includes the drawing of said steel pipe to a flat tubular member with two polygonal areas at those portions of said tubular member which have the greatest distance from each other While those portions which are closest to each other confine a slot establishing communication between said polygonal areas.

References Cited UNITED STATES PATENTS 1,106,053 8/1914 Nichols 287-404 1,959,744 5/1934 Stein 29-4483 2,354,650 8/1944 Burgess 2 914 8.3 2,403,159 7/1946 Widman et al. 29148.3

CHARLES W. LANHAM, Primary Examiner.

E. M. COMBS, Assistant Examiner. 

1. A METHOD OF MAKING A CATERPILLAR TRACK CONNECTOR HAVING TWO BEARING EYES SPACED FROM EACH OTHER IN LONGITUDINAL DIRECTION OF SAID CONNECTOR AND COMMUNICATING WITH EACH OTHER BY A SLOT EXTENDING OVER THE ENTIRE WIDTH OF SAID CONNECTOR, THE STEPS OF; FLAT ROLLING A SEAMLESS STEEL PIPE TO THE APPROXIMATELY OUTER CONTOUR OF THE CONNECTOR TO BE MADE, FINISH SHAPING THE THUR ROLLED STEEL PIPE TO A RATE SHAPE, CUTTING OFF FROM THE THUS SHAPED STEEL PIPE A SECTION CORRESPONDING IN WIDTH TO THE DESIRED WIDTH OF THE CONNECTOR TO BE MADE, AND PRO- 